Torsionmeter



F. T. EDGECOMBE.

TORSIONME'TER. APPLICATION FILED JULY I6, 1920.

-Mw @muted out, 31, 1922,

FHEIJER/CK T 511075@ omge F. T. EDGECOIVIBE.

TORSIONMETER.

APPLICATION FILED IuLv Ie, 1920.

LSQLQ' Patented 0015.31, 1922..

3 SHEETS-SHEET 2.

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FEEDER/cf( ZEncsecomf Patented @ce si, i922.

FREDERICK THOMAS EDGECOMBE, OF DUMBARTON, SCOTLAND.

TORSIONMETER.

Application led July 16, 1920. Serial No. 396,658.

To all whom t may concern.'

Beit known that l, FREDERICK THoMAs Enenooirnn, a subject ot the King ot Great Britain and ireland, and a resident ot' Duinbarton, in the county ot Dumbarton, vScotland, naval architect, have invented certain. new and usetul lmproveinents in yllorsionmet-ers, of which the itollowing is the specitication.

This invention relates to the torsionmeter described in the specilication ot my prior Patent No. 1,065,305, which con'lprises a mechanical torque measuring and measurement multiplying device in combinationwith an electrical indicating device consisting otl a rheostat, in circuit with a measuring instrument in the known manner otl an electrical resistance varying torsionmeter, and having a moving balanced arm driven through gearing from one ot those parts in the mechanical device to which is transmitted a multiplication ot the torque movement.

The balanced arm carries a contacter (or contactors) making contact with an arc (or arcs) of resistance and the contactor is continually rubbing on the rheostat. There is consequently considerable wear ot both contactor and rheostat.

The present invention has tor its object so to improve the construction of the torsionmeter as to 'obviate this disability, by providing means whereby the contactor is held clear ot the rheostat, except at such times as it is desired to bring the instrument intonse to measure the torsion olf a shaft.

rAccording to the invention there is attached `to the transmitter a solenoid operating a. lever which controls the position ol the contacter. rlhe solenoid circuit separate lroni the torsionmeter circuit, and has two independent slip rings and brushes.

In the measuring instrument there is a switch arranged, so that when the key is pressed to obtain a reading ot the torsion, the solenoid circuit is also brought automatically into action.

The solenoid circuit is supplied 'from any convenient source ot power separate from that tor the torsionmeter circuit, such, tor example, as the ordinary ships lighting circuit.

The device be arranged to operate in one or other ot two ways, namely (1) so that the solenoid .is energized in order to keep the contactor clear ot the rheostat, in

which case the solenoid circuit is always in operation except when readings are being taken, and the contactor is at one end ot a separate arm pivoted at its middle on the balanced arm and acted upon at its opposite end by the solenoid lever; or so that the solenoid. is energized in order lo bring the contacter into contact with the rheostat, in which case the solenoid circuit is only used when torsion readings are being taken, and in this case the separate arm carrying the contactor is acted uponat its centre by the solenoid lever and hinged at its end on the balanced arm.

Two illustrative examples of the method or" carrying out the invention are shown diagrammatically on three accompanying sheets of explanatory drawings, Figure 1 of these drawings shows the arrangement ot parts when the solenoid is energized and the contactor clear ot the rheostat, except when torsion readings are being taken, ln Figure 2 the arrangement is such that the solenoid is energized only while readings are being taken. Figure 3 is a plan view corresponding to Figure 2 but with the contractor arm shown at right angles to the solenoid lever. Figures Lland 5 are diagrams ot the electrical connections corresponding respectively to the arrangements shown in Figures 1 and 2.

Referring to the first example (Figures 1 and 4) a solenoid A is attached to a member B the movement ot which relative to a sha't't (l carrying a balanced arm l) is transmitted trom the shaft to be tested by the mechanical multiplying device hereinbetore'referred to. The solenoid plunger A1 is liivotailly connected at its upper end to one end ot a lever E, theother end ci which is t'ulcrumed in a bracket F carried on the inen'iber Located beneath the soienoid lever E and pivoted in a bracket (i attached to the balanced arm D, is a separate arm H, adapted at one end H1 to be operated by'an adjustable screw El in the lever E, and at the other end H2 to engage a contactor pin K. rheostat L ot usual form is carried in the member B and is so positioned as to be engaged by the contacter K when required. The pin K is located in a housing K1 formed in the end ot the balanced arm D and when not operated on by the arm H, is maintained out of contact with the rheostat L by the action ot a spring` K2. The weight carried by the arm D on the side ot the contactor is counterbalanced by a balanced. weight D1 located in the opposite` side ot the arm. Disposed be tween the centre oi the arm D and the end Hl of the arm H is a spring M in compression, which, when the solenoid lever lil is in the raised position, is suficiently strong to overcome the thrust ofthe contactor spring K2 and to maintain the end H3 of the arm H depressed and the contacter in contact with the rheostat.

In operation, when no torsion readings are being taken the solenoid is energized, the end H2 oil the arm H being raised by the artion of the solenoid lever E on the other end oi this arm, and the contacter beingl in tiunmaintained out of engagement with the rheostat by the spring K2. Then however the solenoid circuit .is broken (that is, when readings are to be taken) the plunger A1 rises, releasing the presf ire oil.i the screw El on the end oi the arm H and allowing the spring M to force down the other end of the arm and bring the contacter and rheostat into engagement.

' Slip rings M, M and brushes N, N (Figure 4L) are provided for the rheostat or indicator circuit O, and rings M1, M1 and brushes l 1, N1 for the solenoid circuit P, which is independent ot the former. The balanced arm D is earthed through the member B in usual manner. rl`he solenoid circuit is controlled by a switch P1 which is interlocked with the key of an ammeter or other measuring instrument in the indicator circuit. The switch P1 is normally on7 but is automatically cut oil' when the measuring instrument is brought -into the indicator circuit. l

ln the second example (Figures 2, 3 and 5) the bracket G is secured to the balanced arm D at the opposite end from the contacter K, the arm H in this case being hinged at one end to the bracket G secured at the other to the contacter pin l( and adapted to be opera-ted on its centre by the screw lil]- o the solenoid lever. solenoid lever is normally inoperative, the contacter being maintained out olA engagen nient with the rheostat by the action o'l" the spring K2. On the solenoid being energized, the screw El bears down on the centre of the rarm H and depresses the contacter against the action of its spring K2 into engagement with the rheostat L. As in the iirst example the switch P1 controlling the solenoid circuit is interlocked, with the press key of the measuring instrument in the indicator circuit, but in this case the switch P1 is normally olif, contact being automatically made and the solenoid energized, when the key of the measuring instrument is depressed to bring the latter into circuit.

ln both the 'foregoing examples the solenoid A is attached to the transmitting member B which is normal to the axis of, and revolves with the shattthe torsion in which lnlthis example thev isbeing measured. Centrifugal torce produces a considerable pressure between the solenoid plunger A1 and its circular casing, and means have to be provided in order to prevent the frictional resistance caused by this pressure from overcoming the initial pull of the solenoid. To this end two small rollers A2 fitted in slots A3 in the plunger A1 (Figure 2) are located in the plane passing through the centre line of the solenoid and that of the shaft under test, and are arranged to bear on the plungerr casing at the side thereof remote from the axis of the shaft.

l. ln torsionmeters oi the type referred to in which torque is measured by the relative movement between two members, a oontaeter, a balanced arm carrying the same, a rheostat over whichv the contacter is adapted to move during operation of the torsion- 'meter, electro-magnetically operated means fori bringing the contacter into and out ot electrical engagement with the rheostat,and manual switch means controlling said rheostat and electro-magnetically operated means as set forth.

,2. ln a torsionmeter oit the construction specified in cla-im 1, a solenoid attached to the member carrying the rheostat and having a plunger; a lever hinged at one end to this member and pivotally connected at the other to the solenoid plunger; a balanced 'arm at one' end provided at one end with a housing, and counterbalanced Iat the other, a con taeter pin supporte-d in said housing, and a separate arm or lever pivoted on the balanced arm and coacting with the solenoid lever and with the contacter, as set forth.

3. In a torsionmeter of the construction specified in claim l, a solenoid attached to the member carrying the rheostat, and having` a [dung-er, a lever hinged at one `end to this member and pivotally connected with the otherto the' solenoid plunger, a balanced arm provided at one end with a housing, and counterbalanced at the other, a contacter pin supported in said lmusing, a separate arm or lever extending between the center of the balanced arm and the cont-actor and pivoted at or near its center` to the balanced arm, and eoacting atene end with the solenoid lever and at the other with the contacter, and spring devices between the center of the balanced arm and the-adjacent end of the separate arm and between the contacter pin and its housing, substantially as set forth. I

4, In a torsionmeter ofthe construction specified in claim 1, a solenoid attached to the member carrying the rheostat, andhaving a plunger, a lever hinged to this member and pivotally connected to the solenoid plunger, a balanced arm provided at one vend with a housing, and counterbalanced at the other, a cont-actor pin supported in said housing` a separate lever pivoted to the balanced arm, and secured at its other end to the contactor and co-acting at a point adjacent to the center of the balanced arm with the solenoid lever, and a spring device between the contacter and its housing.

5. ln a torsionmeter ot the type described i in which the torque is measured by the relative movement between two members, a contacter', a balanced arm carrying the same, a rheostat over which the contacter is ada-pt ed to move during the operation of the torsionmeter, and means for bringing the contactor into and out olf electrical engagement wi th the rlieostat, said means comprising :i solenoid attached to the member carrying the rheostat and having a slotted plunger, and rollers mounted in the slots et the solenoid plunger, said rollers being located in the plane passing' through the center line of the solenoid and that of the shaft under test, and bearing on the plunger on the solenoid casing at the side thereof remote from the axis oi the shaft.

6. ln torsioinneters off 'the type described, in which the torque is measured by the relative movement between two members, a contactor, a balanced arm carrying the same, a rheostat over which the contactor is adapted to move during' the operation of the torsionmeter, and means for bringing the contactor into and out ot electrical engagement with the rheostat, in combination with a torsionmeter circuit, an electrical measuring instrument in the circuit, a switch controlling the circuit, an independent solenoid circuit, a switch. controlling the solenoid Circuit and interlocking with the switch ot the measuring instrument to automatically bring the contactor into engagement with the rheostat simultaneouslyv with the closing` of the measuring instrument circuit.

In testimony whereof I have signed my name to this specification.

FREDERCK THMS EDGECOMBE. 

